What is the maximum minimum magnification I can get away with?

007

New member
...

You have to be aware with a reflector that although the objective is 76mm, you lose some light because of the reflector on the front. Not sure of the exact amount, but it may be around 25%.

...
OK, well I have asked the question of a seller of one of these things...

What is the diameter of the centre obstruction (secondary reflector attached to the rear of the objective lens)?

I have just received a reply which states it is 18mm.

So - pulling out the old calculator again I think I can figure out what it's effective equivalent obstruction free diameter would be...

sqrt(78^2-18^2) = 75.8946638

So in actual fact the 78mm lens is equivalent to a 75.9mm lens. If I have done my sums correctly, that is 2.7% drop in diameter and a 5.3% drop in area.

OK, a 76mm lens is not an 80mm lens but I am also looking at the compactness. It comes with a 26-78x zoom lens - judging by the comments received, the lower end of the magnification will be just about right and the mid-higher end should be fine for basic stargazing. It also comes with a fixed 19.5x lens with wider fov. I like the fact it takes any 1.25" lens too.

I am currently watching a couple of these in auction, hopefully I will win one of them. I'll let you know if I do, however I won't be able to give an accurate review as I am not experienced enough. i will however let you know whether I like it or not.


p.s. can someone delete post 16 It has been duplicated and superceded with post 17, but I can no longer edit it.

many thanks
 

Flying Whale

New member
OK, well I have asked the question of a seller of one of these things...

What is the diameter of the centre obstruction (secondary reflector attached to the rear of the objective lens)?

I have just received a reply which states it is 18mm.

So - pulling out the old calculator again I think I can figure out what it's effective equivalent obstruction free diameter would be...

sqrt(78^2-18^2) = 75.8946638

So in actual fact the 78mm lens is equivalent to a 75.9mm lens. If I have done my sums correctly, that is 2.7% drop in diameter and a 5.3% drop in area.

OK, a 76mm lens is not an 80mm lens but I am also looking at the compactness. It comes with a 26-78x zoom lens - judging by the comments received, the lower end of the magnification will be just about right and the mid-higher end should be fine for basic stargazing. It also comes with a fixed 19.5x lens with wider fov. I like the fact it takes any 1.25" lens too.

I am currently watching a couple of these in auction, hopefully I will win one of them. I'll let you know if I do, however I won't be able to give an accurate review as I am not experienced enough. i will however let you know whether I like it or not.


p.s. can someone delete post 16 It has been duplicated and superceded with post 17, but I can no longer edit it.

many thanks
You could also try googling Nipon scopes uk. There is a web site where you can buy them direct, without having to wait on a bid. They are pretty reasonable (from memory about ?54, but I am not sure what eye pieces that came with)
 

007

New member
You could also try googling Nipon scopes uk. There is a web site where you can buy them direct, without having to wait on a bid. They are pretty reasonable (from memory about ?54, but I am not sure what eye pieces that came with)
That would be about right, as the 9-27x50 is ?40 - if only they listed the 26-78x78 in their shop and not just in their catalogue.

still, I could be looking at a steal through the auction site - you never know.

[edit] Found one shop listing it at ?95 and out of stock :( - think I'll concentrate on the auctions for now.
 

scalawag

New member
Well,

My 20-60x80 S&B Saharah arrived yesterday afternoon, and all I can say is "it's huge!!!!". Seriously though initial tests at home seem good the picture quality seems very good and the magnification is great too (though I suspect I won't be needing too much magnification).

Looks really well built and a nice stay on case too.

I will post back again when I have tried it on the line (which could take some time as I am going to be very self conscious setting this sucker up!!!).

Seems like a good buy though.
 
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